You have a browser of one tab where you start on the homepage and you can visit another url, get back in the history number of steps or move forward in the history number of steps.
Implement the BrowserHistory class:
BrowserHistory(string homepage) Initializes the object with the homepage of the browser.void visit(string url) Visits url from the current page. It clears up all the forward history.string back(int steps) Move steps back in history. If you can only return x steps in the history and steps > x, you will return only x steps. Return the current url after moving back in history at most steps.string forward(int steps) Move steps forward in history. If you can only forward x steps in the history and steps > x, you will forward only x steps. Return the current url after forwarding in history at most steps.\n
Example:
\n\n\nInput:\n["BrowserHistory","visit","visit","visit","back","back","forward","visit","forward","back","back"]\n[["leetcode.com"],["google.com"],["facebook.com"],["youtube.com"],[1],[1],[1],["linkedin.com"],[2],[2],[7]]\nOutput:\n[null,null,null,null,"facebook.com","google.com","facebook.com",null,"linkedin.com","google.com","leetcode.com"]\n\nExplanation:\nBrowserHistory browserHistory = new BrowserHistory("leetcode.com");\nbrowserHistory.visit("google.com"); // You are in "leetcode.com". Visit "google.com"\nbrowserHistory.visit("facebook.com"); // You are in "google.com". Visit "facebook.com"\nbrowserHistory.visit("youtube.com"); // You are in "facebook.com". Visit "youtube.com"\nbrowserHistory.back(1); // You are in "youtube.com", move back to "facebook.com" return "facebook.com"\nbrowserHistory.back(1); // You are in "facebook.com", move back to "google.com" return "google.com"\nbrowserHistory.forward(1); // You are in "google.com", move forward to "facebook.com" return "facebook.com"\nbrowserHistory.visit("linkedin.com"); // You are in "facebook.com". Visit "linkedin.com"\nbrowserHistory.forward(2); // You are in "linkedin.com", you cannot move forward any steps.\nbrowserHistory.back(2); // You are in "linkedin.com", move back two steps to "facebook.com" then to "google.com". return "google.com"\nbrowserHistory.back(7); // You are in "google.com", you can move back only one step to "leetcode.com". return "leetcode.com"\n\n\n\n
Constraints:
\n\n1 <= homepage.length <= 201 <= url.length <= 201 <= steps <= 100homepage and url consist of '.' or lower case English letters.5000 calls will be made to visit, back, and forward.Compiled with clang 11 using the latest C++ 17 standard.
Your code is compiled with level two optimization (-O2). AddressSanitizer is also enabled to help detect out-of-bounds and use-after-free bugs.
Most standard library headers are already included automatically for your convenience.
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Python 2.7.12.
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\\r\\n\\r\\nFor Map/TreeMap data structure, you may use sortedcontainers library.
\\r\\n\\r\\nNote that Python 2.7 will not be maintained past 2020. For the latest Python, please choose Python3 instead.
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Your code is compiled with level one optimization (-O1). AddressSanitizer is also enabled to help detect out-of-bounds and use-after-free bugs.
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\\r\\n\\r\\nFor hash table operations, you may use uthash. \\\"uthash.h\\\" is included by default. Below are some examples:
\\r\\n\\r\\n1. Adding an item to a hash.\\r\\n
\\r\\nstruct hash_entry {\\r\\n int id; /* we'll use this field as the key */\\r\\n char name[10];\\r\\n UT_hash_handle hh; /* makes this structure hashable */\\r\\n};\\r\\n\\r\\nstruct hash_entry *users = NULL;\\r\\n\\r\\nvoid add_user(struct hash_entry *s) {\\r\\n HASH_ADD_INT(users, id, s);\\r\\n}\\r\\n\\r\\n\\r\\n\\r\\n2. Looking up an item in a hash:\\r\\n
\\r\\nstruct hash_entry *find_user(int user_id) {\\r\\n struct hash_entry *s;\\r\\n HASH_FIND_INT(users, &user_id, s);\\r\\n return s;\\r\\n}\\r\\n\\r\\n\\r\\n\\r\\n3. Deleting an item in a hash:\\r\\n
\\r\\nvoid delete_user(struct hash_entry *user) {\\r\\n HASH_DEL(users, user); \\r\\n}\\r\\n\\r\\n\"], \"csharp\": [\"C#\", \"\\r\\n\\r\\nYour code is compiled with debug flag enabled (/debug).
Node.js 16.13.2.
Your code is run with --harmony flag, enabling new ES6 features.
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\\r\\n\\r\\nFor Priority Queue / Queue data structures, you may use datastructures-js/priority-queue and datastructures-js/queue.
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Some common data structure implementations are provided in the Algorithms module: https://www.rubydoc.info/github/kanwei/algorithms/Algorithms
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Go 1.17.6.
Support https://godoc.org/github.com/emirpasic/gods library.
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Most libraries are already imported automatically for your convenience, such as array, bisect, collections. If you need more libraries, you can import it yourself.
\\r\\n\\r\\nFor Map/TreeMap data structure, you may use sortedcontainers library.
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